Continuous control apparatus with linear motion



Feb. 18, 1947. M. N. YARDENY 2,416,274

CONTINUOUS CONTROL APPARATUS WITH LINEAR MOTION Filed May 23, 1944 3 Sheets-Sheet 2 MICHEL M Y4 RDENY INVENTOR ATTORNEY Feb. 18, 1947. YARDENY 2,416,274

CONTINUOUS CONTROL APPARATUS WITH LINEAR MOTION Filed may 25, 1944 v s Sheets-Sheet s Move: A YARDE/V) INVENTOR ATTO R N EY Patented Feb. l8, 1947 UNITED STATES PATENT OFFICE CONTINUOUS CONTROL APPARATUS WITH LINEAR MOTION Claims. 1

My invention relates to control apparatus and has particular reference to apparatus for placing an object or a useful load in any desired position within the limits of movement of the apparatus.

One object of my invention is to provide means for moving a useful load controlled by the control apparatus in a substantially rectilinear line. Such straight or rectilinear motion of the useful load is advantageous for certain fields of application where it is desired to effect a movement other than rotary or where a rotary motion must be produced by the agency of members having a reciprocating motion.

One desirable application of my control apparatus consists in an arrangement for the remote control of so-called trim tabs on airplanes, used in connection with the control of the movement of the wing ailerons, rudders and stabilizers. trim tabs in such cases are provided with lugs or cranks pivotally connected with links operated by control devices having linear or reciprocal motion.

Another useful application of my device consists in an arrangement for remote control of variable stroke pumps in which stroke and rate of delivery are controlled during the operation of the particular pump or similar device.

Another object of my invention is to provide means to convert the rotary motion of drive means used with my apparatus into a linear motion which may be applied directly to the load or further converted into the motion along a curve. According to one embodiment of my invention, I accomplish this by introducing a threaded connection between the control elements and a driven member or drive means which operates the useful load.

Another object of my invention is to provide means to stop positively the drive means when the load is placed in the desired position within predetermined limits.

Another object of my invention is to provide means to stop positively the drive means when the latter reaches either one or the other of the predetermined limiting positions regardless of the position of the control elements of the apparatus. In one embodiment of my invention I accomplish this by deenergizing the operating motor and using an automatic brake, and in another embodiment I provide means to reverse the motor for an instant when it overruns the stopping point at the end of its path by inertia.

Another object of my invention is to prevent hunting of the motor or of the -movable parts when the desired-position is reached bythe load,

and also to stop positively the motor, preferably by electrodynamic means.

Another object of my invention is to provide improved means for indicating the correct position reached by the load.

Another object of my invention is to provide an arrangement whereby all the control elements and operating relays are mounted together at a control point, leaving the operating motor free of any such control elements and devices.

Other and further objects of my invention will be apparent from the description and the appended claims.

My invention is more fully described in the accompanying specification and drawings 'in which- Fig. 1 is a diagrammatic view of a control apparatus according to my invention;

Fig. 2 is a sectional view taken on the line 2 2 of Fig. '1;

Fig. 3 is a detail view of control elements employed in my control apparatus;

Fig. 4 is a diagrammatic view of a modified control apparatus;

Fig. 5 is a diagrammatic View showing an aplication of my control apparatus for the operation of a trim tab of an airplane; and

Fig. 6 is asectional view showing an application of my control apparatus for the remote control of a variable stroke pump.

The control apparatus as shown by way of an example in Figs. 1, 2 and 3, comprisesa tubular member I having an extension 2 at the outer end preferably provided with'a hole 4 for pivotal or other connection to a useful load (not shown). The tube is provided with lugs 5 (Fig. 2) sliding on a base plate 8 and guided by rails 9. A threaded rod or screw IE3 is fastened at one end to theextension 2' and is engaged by a nut H at the end of an inner or driving tube l2. The latter is provided with a bearing l' ro-tatively and slidably-engaging the inner surface of the outer tube 1. Asimilar bearing i5 is fitted inside the outer tube I for guidingthe lower end of inner tube I2.

The lower end of the inner tube l2 mounts a Worm gear I! engagedby a worm is on a shaft i9 connected by an automatic electromagnetic clutch and brake 29 of a conventional type with a Shaft/290T an armature 2| of a motor gener ally designatedby the numeral 22. The magnet coil of clutch and brake 29 is connected with the armature 2! by alead 21 by leads 3 5, 5:5 with the terminal 36 of a source of current 3'5, and so arranged-thatthe clutch and brake engages the two shafts together when the motor 22 is energized.

The motor 22 may be of any type and size suitable for operating the load and is shown as a re- Versible series wound D. C. motor, having two reversing windings 52, 33, connected in series with the armature 2i. The free ends of the windings are connect-ed by leads 38, 39 with relay contact points lii, II and by leads 52, 63 to a second pair of contact points 14, t5, the contact points being arranged to be engaged by arm-s 58, 39, t and El respectively of two double pole double throw relays having magnet coils 52 and 53. The relay arms 56, 5i are connected together by a lead 55 and the relay arms 3, 49 are connected to the terminals of an armature 56 of a control motor generally designated it and having a permanent field magnet ill. The ends of the relay coils are connected together by a lead 58 which is connected by leads 555, with the terminal 36 of the source of current 3 The other end of the relay coil is connected by lead (it, disconnecting switch I52 and a lead BI with a brush E l engaging a collector ring 65 on an insulation disc 66, the other coil 53 being connected by lead 68, switch iii and lead 69 with a brush II engaging a collector I2. The collector rings 65, I2 are connected with control segments M, iii separted by gaps It, H. The disc 66 is mounted for rotation on a shaft i8 and is engaged by a friction or gear wheel 8% mounted on a shaft 8! operated by the motor 36. The segments it, 75 are slidably engaged by a contact arm 86 mounted on the shaft it which can be manually rotated bya knob 85 at the end of the shaft. The end of the contact arm t l may be provided with a contact ball 8? (Fig. 3). The ends 853, 98 of the segments It, 75 are gradually raised toward the gap IS and are steeply bent downwards into the gap, forming a seat for the ball 81. The ends 85, 96 are preferably made resiliently flexible so that they can yield under pressure of the ball thereby maintaining the ball engaging and bridging the gap while allowing a small relative resilient displacement between the segments and the contact arm. A recess 88 may be provided in the disc 86 for the flexible ends 89, as. This arrangement allows the motor to be stopped while the gap is bridged and before the force of inertia may cause the contactor to leave the gap.

The tubular member I (Fig. 1 and Fig. 2) is provided with a lug 92 on a yoke 83 slidably fitted on the tube and locked in a desired position by a set screw 9 t. Lug 92 serves to control switches 52 and iii.

The disconnecting switches 62, it! are mounted on plates st carried by the base 3 and fastened by screws or bolts 9?, the base having elongated slots lit? for allowing longitudinal adjustment of the switches on the base.

The position of the movable member 5 or of the useful load is indicated by an indicator Iilil calibrated in suitable units of linear measurement such as inches and their fractions. The indicator may be electrically operated by electric current from a potentiometer II or other suitable voltage varying device. The potentiometer is connected by leads I532, I63 with the terminal lfl 'l of the source of current 3? and by leads Itlfi, with the other terminal 35. The indicator is connected by a lead IN, a variable resistor I653, and a lead Me with a contact arm IIQ of. the potentiometer, and by a lead III with the terminal 3b of th source of current 3 The arm lid is connected by gears H2, H3 with an extension shaft lit connected with the worm gear I7. Ratio of the gears H2, H3 is so selected that the total travel of the member I or of the useful load corresponds to the maximum or suitable travel of the contact arm Hi1, and the meter use is adjusted to indicate this travel on its scale. Th resistor I tit serves to adjust the zero point of the meter.

The relay arms til, ill, when attracted by the energized coils, engage contact points H3, H9 connected by a lead IZII with the terminal 36, and the arms 5t5i engage contact points I 2!, I22 connected by leads I23, IE3 with the terminal 31.

The operation of my apparatus is as follows:

Assuming that the member I is placed in its most inward (or the lowest in Fig. 1) position in which the switch 62 is opened by lug 92 renderingthe relay coil 52 inoperative, and that it is desired to move the load in the opposite direction by moving the member I outward (or upward in Fig. 1), then knob is turned in a clockwise direction, causing the contact arm 84 with its contact ball M to engage the segment T5. The relay coil will be now energized through closed switch iii, attracting the arms 59 and 5 I Current will pass. from the terminal I84 of the source of current 3? through leads I03, I23, contact point 22, arm 55, lead 5'5, arm 58, point 44, lead 42 point it, arm 58, armature 56, arm 49, point H9, and leads 52 35 to the other terminal 36. The armature will rotate, turning the pinion 8t and the disc 6%, the disc being turned in a clockwise direction, causing the gap it to follow the displaced contact arm at.

Current will also flow from the point it] through the lead 3Q, winding 32, armature 2i of the load or controlled motor 22, lead 2?, the coil of the automatic clutch and brake Z9, and leads 34, 35 to the terminal 236. The other winding 33 will be disconnected, relay 53 being energized. The armature 2! will rotate in a direction for moving the member I outward. This movement will be continued until the gap 75 reaches the contact arm t l, then both relay coils will be energized so that all four relay arms 63, 43, M, 5! will be attracted, disconnecting the circuits through both motor armatures 2i and 5E. The armature 56 will be short circuited by the lead I20 and will be dynamically braked by the permanent magnetic field. The clutch and brake coil being deenergized, thereby causing driving shaft I9 to be abruptly and positively stopped.

If the arm 34 is displaced again, both motors will be restarted and stopped again when the gap it catches up with the contact arm. Hence the motors will simultaneously start and stop as controlled by the movement of the contact arm, although the speed of the load motor may be different from the speed of the control motor. Both motors will be finally stopped When the arm 84 is no longer displaced, the true position of the load or of the member I being indicated by the indicator lilil.

The indicator is necessary with this arrangement due to the fact that the true position of the load or of the member I may not correspond to the position of the contact arm 8 It may be necessary to make several revolutions of the contact arm St to cover the complete range of movement of the load as determined by the end positions of the member I. The member I may be stopped in any intermediate position. When the extreme outward position is reached, the lug 92 will open the switch it}, disconnecting the relay coil 53 and stopping the motors. No further movement of the load in this direction will be possible, but coil 52 may be energized for the reverse movement by placing arm 84 on segment "It, switch 62 being closed.

For a more or less large movement of the load, 5 the contact arm is simply moved to a position in which th contact ball 3'! occupies the position indicated in dotted lines in Fig. 3 and is then released. The segment will then rotate together with the contact arm, the latter being held by friction in its position. This common rotation will continue until the contact arm is stopped by holding the knob Depressions I or projections may be provided in the segments M, 5 to increase the frictional resistance to displacement of the ball 8?.

A modified apparatus is shown in e. A screw member 136 is connected at one end directly to the worm gear I? and is engaged by a nut I'M on an outer tubular member the latter being of a construction similar to the member l of Fig. l and being provided with similar lugs for guiding its movement between the rails 9. Instead oi the electromagnetic clutch shown in Fig. l elec tromagnetic brake is provided.

The motors and their connections are similar to the corresponding parts of Fig. l and are accordingly designated by the same respective mimerals. The only change is in that the load motor 22 is connected by the leads 33, 38 to the points only, and the points til, 43 are connected by a lead its to the lead I23. The advantage of such a connection is that the upper relay contact points it, 5 are used only for the load mtor 22 and the lower points All, ii are used only for the control motor. to. The control motor in this case is braked dynamically when the relays are both energized or deenergized. The relay connections are modified in that both relay coils are continuously energized, the coils being connected in a closed cuit by a lead its extending from the terminal through resistors I37, respectively, leads l39 respectively and leads 5%, 59, to the terminal The contact arm is connected by a lead Mil with the lead es so that one or the other relay coil is short circuited when the contact arm 34 is moved into engagement with one or the other of the segments and i5.

The relay coil is connected by leads 533, with a contact point hi2 normally connected by a contact plate with a contact point I 24 connected lead 51 with the brush 54 of the control disc The plate M3 is mounted on an insulation block 245 supported on a resilient arm I45 with a contact point I ls normally separated from a corresponding contact point 55s on a resilient arm E5? both arms being supported on the switch base adjustably fastened to the as scr-vs The arm l -l-t is connected by leads I53, H39 the relay coil second arm i552 bei rg connected by leads use, 5e, 58 with the other terminal of the coil 5 switch base 95 is mounted at the other base is for resi" nt arms 559 points let. the arm I53 being 2 .ected by leads i853 with one terminal of t e coil the other i 52 being connected by 'eads i5 1, 58 with the 0 or terminal of the oil tact points lethal are normally cor'ie by a 553. Contact nected by leads Hill with relay coil and contact point i=3 s connected by lead wit" the brush 1 i.

The indicator we is provided with adjustments A similar end of the ontac for zero and maximum points. These adjustments include a second potentiometer I10 connected by leads I l 1, 172 with the terminals of the first potentiometer NH. The second potentiometer is connected by an adjustable contact point 113 with a resistor I'l l connected by an adjustable contact point 515 with the lead IQ! of the indicator I08, the other indicator terminal being connected by a lead IIB with the arm Ill). The contact point I15 adjusts the maximum position of the indicator in accordance with the most outward position of the movable member I32, and the point H5 adjusts the zero position of the indicator I56 for the starting position of the member I32.

Both relay coils are connected in a circuit, when an operating switch I76 is closed, a circuit for the relays being closed from the terminal I04 and closed switch I'ifi through lead I35, resistors I36, i3! and leads I38, I35, connected in parallel, through coils 52, 3 and leads 5%, 59 and 35 to the other terminal 35. However both relay coils will be short circuited and release their arms as long as the contact arm 84 occupies the gap 16. The coil 52, for instance, is by-passed by the leads 5s, lzilyarm 84, segment l4, brush 65, lead BI, point IM, plate [43, point I52, leads 60, I38, resistor {35, and lead I16. The coil 53 is similarly by-passed. Both motors are deenergized and the control motor armature 55 is dynamically braked when both relay coils are short-circuited.

The operation of the device is as follows:

It be assumed that it is desired to move the load and the tube I32" outward and that it will be necessary for this purpose to move the contact arm 84 to the right,

When the contact arm 85 is moved to the right by turning the knob 85, the coil 53 will remain short-circuited and hence inoperative, the coil 53 being short-circuited from the terminal I at and switch I16 through the lead l 5, resistor r31, leads I35 63, point E66, plate I68, point Ifil', lead 61-3, brush 'lI, ring l2, segment 15, contact arm 84, and leads 5%, 59 and 35 to the other terminal 36. The coil 53 being short circuited, the arms 49, 5i remain released, engaging the points M and 55 respectively. Coil E2 attracts its arms 45, 52, the short circuit of this coil being now removed. Both motors will be energized, current for the load motor 22 passing from the terminal I64 and switch H6 through the leads 33,123, point I2I, arm 50, lead 55, arm 5|, point 45, lead 39, winding 33, armature 2!, lead 21, the coil of clutch and brake 29, and leads S4, 35 to the other terminal 36. The control motor 45 will be similarly energized, current passing from the terminal Iild and switch through leads I 93, I23, I34, point 4!, arm 49, armature 55, arm 48, point H 8, and leads I29, 35 to the other terminal 36. The rotation of the motors will continue until the gap 76 reaches the contact arm 85, the disc 66 being rotated by the armature 58. The motors will be stopped when the gap is bridged by the contactv arm 84.

If the rotation of contact arm 85 is continued, the motors will continue to rotate until they are finally stopped by the finger or lug 92 operating the corresponding limit switch. Thus if the movement or the tube 32 was inward (or downward on the drawing), the lug 92 will first deflect the arm I58, disconnecting the leads 63, 59 at plate I63 and breaking the short circuiting connections of the relay coil allowing the coil to be energized by the current through the resistor I37. Both coils are. now energized, attracting both sets of the arms is, 49, 50, El and stopping the motors. If the load drive overruns its stopping position by inertia, the arm I58 will be forced into contact with the arm I59, short circuiting the coil '52 by connecting leads H53 and Hit. With the coil 53 alone energized, the motors will be reversed, current now passing through the other field winding 32 of the load motor and in the opposite direction through the armature 56 of the control motor.

A suitable arrangement may be provided for preventing or suppressing oscillations of the motor or drive means when the contactor 84 reaches the gap, similar to the arrangement of Fig. 3 and which involves the use of resilient conducting members and raised points at the can. I

Any tendency of the motors to oscillate when the limit switches are operated may be suppressed in a similar manner, principally by providing a suflicient length of resilient travel for the contact arms r58, I55 and M8, l52 so that the motors will remain deenergized during a short travel of the moving parts by inertia until the motors are stopped or even momentarily reversed.

The remote control system according to the invention can be used for operating various devices in which an object must be moved to any desired distance within certain limits. One of such possible and practical applications is shown in Fig. which illustrates operation of a trim tab i813 of an airplane, the tab being pivoted at 8! to the end portion I83 of an aileron, rudder or elevator. The tab is provided with a lug E35 pivotally connected at L86 to one end of a rigid rod l8! whose other end is pivotally connected to the end portion 2 of member l such, for instance, as shown in Fig. 1. The extreme positions of the tab are shown in dotted lines, the pivot l88 correspondingly occupying end positions 58 5, i556". The end 2 of the apparatus will then occupy positions 2, 2". The movable portion l2 of the apparatus is operated by the motor 22 through suitable gears l1, l8.

Another practical application of my apparatus is shown in Fig. 6 which illustrates a variable displacement pump having a seaied housing lili! with an adjustable ring till inside. The ring is fulcrumed at I82 and is urged by a spring la? into a position approximately concentric with a tubular shaft rotated by a suitable source of power. Shaft fill mounts cylinders with pistons 2G2, 233, 2%, 2&5, 2&5, with rollers 258 at the ends of their rods 25 i, the rollers engaging the inside surface of the ring itl. Springs 2l5 urge the pistons outward. The shaft 2 ll ror tates on a stationary member 256, with intake channels 2l8 and exhaust channels Ell: formed between member 2&5 and a central core ESQ. These channels communicate with the cylinders by ports 232 when the corresponding channels and ports in stationary member 255 and rotary shaft 2i i are in registry. The channels are connected respectively to intake and exhaust manifolds in a conventional manner.

The pistons 2&2, 2&3, are moved inward because of the eccentric position of the ring while the pistons 255, 293, as? are moved outward.

The length of the piston stroke is varied depending on the position of the ring lsl, When it is desired to make the adjustment more or less frequently and even during the operation of the pump, this can be accomplished by the use of a remote control apparatus according to the in vention, The operating portions of the apparatus include a plunger 225 sliding in a cylinder 226 and prevented from rotation by a set screw 22! the end of which slides in a longitudinal groove in member 225, The plunger is threaded on a screw 228, having a flange 229 retained by a cap 230. The screw is fastened to the worm gear I1 engaged by the worm l8 mounted on the end of the shaft of the motor 22. The motor is mounted on a bracket 23! attached to the casing lilfi. The ports may be staggered to provide for a substantially continuous pumping action.

I claim as my invention:

1. A control apparatus comprising a pair of independently movable control elements; a reversible control motor operatively connected with one of the control elements, the other control element being arranged to be moved by other means; reversible drive means constructed to move in a substantially straight line and arranged to operate a useful load; a second motor for operating the drive means; means to electrically control both motors by the relative position of the control elements and to deenergize the motors in any desired position of the load in response to the control elements occupying a predetermined relative position; limit switches constructed and positioned to deenergize both the motors and to stop the drive means in either direction at predetermined extreme positions thereof, thereby limiting the movement of the drive means independently of the control elements; and reversing switches, one reversing switch being positioned beyond each corresponding limit switch for reenergizing the load motor in reversed direction when the drive means overruns by inertia its stopping position as determined by the respective limit switch.

2. A control apparatus comprising a pair of independently movable control elements; a re-- versible control motor operatively connected with one of the control elements, the other control element being arranged to be moved by other means; reversible drive means arranged to operate a useful load; a second motor for operating the drive means; means to electrically control both motors by the relative position of the control elements and to deenergize the motors in any desired position of the load in response to the control elements occupying a predetermined relative position; limit switches constructed and positioned to be opened by the drive means for deenergizing both the motors and stopping the drive means in either direction at predetermined extreme positions thereof, thereby limiting the movement of the drive means independently of the control elements; and reversing switches, one reversing switch being positioned beyond each corresponding limit switch to be closed by the drive means for reenergizing the load motor in reversed direction when the drive means overruns by inertia its stopping position as determined by the respective limit switch.

3. A control apparatus comprising a pair of independently movable control elements; a reversible control motor operatively connected with one of the control elements, the other control element being arranged to be moved by other means; reversible drive means arranged to operate a useful load; a second motor for operating the drive means; means to electrically control both motors by the relative position of the control elements and to deenergize the motors in any desired position of the load in response to the control elements occupying a predetermined relative position; limit switches constructed and positioned to be opened by the drive means for deenergizing both the motors and stopping the drive means in either direction at predetermined extreme positions thereof, thereby limiting the movement of the drive means independently of the control elements; and reversing switches, one reversing switch being positioned beyond each corresponding limit switch to be closed by the drive means for reenergizing the load motor in reversed direction when the drive means overruns by inertia its stopping position as determined by the respective limit switch; each of said reversing switches being arranged to be reopened by the drive means upon reversal prior to the re-closing of the corresponding limit switch for stopping the motor thereby preventing hunting of the load motor.

4. A control apparatus comprising a pair of independently movable control elements; a reversible control motor operatively connected with one of the control elements, the other control element being arranged to be moved by other means; reversible drive means arranged to operate a useful load; a second motor for operating the drive means; means to electrically control both motors by the relative position of the control elements and to deenergize the motors in any desired position of the load in response to the control elements occupying a predetermined relative position; limit switches constructed and positioned to be opened by the drive means for deenergizing both the motors and stopping the drive means in either direction at predetermined extreme positions thereof, thereby limiting the movement of the drive means independently of the control elements; and reversing switches, each of said reversing switches including two resilient contact members normally spaced apart and arranged beyond a corresponding limit switch to be closed by the drive means for reenergizing the load motor for movement of the drive means in reversed direction when the drive means overruns by inertia its stopping position as determined by the respective limit switch; said reversing switches being constructed and positioned to be released by the drive means for opening the same prior to the reclosing of the respective limit switch in response to a movement of the drive means in reversed direction thereby stopping the load motor.

5. A control apparatus as described in claim 2, wherein said limit switches and reversing switches are adjustably supported for adjusting the positions of the said switches in which they are operated by the drive means.

MICHEL N. YARDENY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 708,074 Allen Apr. 9, 1929 1,835,907 Shiland Dec. 8, 1931 2,342,717 Yardeny Feb. 29, 1944 FOREIGN PATENTS Number Country Date 574,666 French July 17, 1924 127,755 German Jan. 29, 1902 264,401 German Sept. 24, 1913 

